1. Field
Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to method and apparatus for aligning downlink discontinuous reception patterns in multiflow High-Speed Downlink Packet Access (HSDPA).
2. Background
Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. One example of such a network is the Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN). UMTS is a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). UTRAN is the radio access network (RAN) defined as a part of UMTS. UMTS, which is the successor to Global System for Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-Code Division Multiple Access (W-CDMA), Time Division-Code Division Multiple Access (TD-CDMA), and Time Division-Synchronous Code Division Multiple Access (TD-SCDMA). UMTS also supports enhanced 3G data communications protocols, such as High Speed Packet Access (HSDPA), which provides higher data transfer speeds and capacity to associated UMTS networks.
As demand for mobile broadband access continues to increase, research and development continue to advance UMTS technologies—not only to meet the growing demand for mobile broadband access, but to advance and enhance user experience with mobile communications.
As an example, Multi-Point (MP) HSDPA has been recently introduced, in which plural cells can provide high-speed downlink communication to a mobile station, such that the mobile station is capable of aggregating the transmissions from those cells, within the same frequency carrier. In HSDPA MP transmission (TX), a data stream is split for two or more cells to transmit. In intra-NodeB MP TX, where the mobile station is served by two or more cells in the same NodeB, a single Medium Access Control (MAC) entity is shared by the two cells, and thus the split can occur at the MAC layer. However, in inter-NodeB MP TX, where the mobile station is served by two cells in different NodeBs, the MAC entity at each NodeB is separate.
As a relatively new system, various issues arise in this system that may not have been addressed in other downlink carrier aggregation systems such as DC-HSDPA. Thus, there is a need to identify and address issues relating to system-level architecture, packet flow control, mobility, and others.